Locked action rifle for automatic and semi-automatic selective firing



May 1%? A. MILLER ETAL 3731891192 LOCKED ACTION RIFLE FOR AUTOMATIC ANDSEMI-AUTOMATIC SELECTIVE FIRING 8 Sheets-Sheet 1 Filed Feb. 12, 1965 May9., 1196? A. MILLER ETAL 2 t e e h Qw S t e e h S D N 8 A G CN IT. R AT.MP 0 TE UV AT. T RC OE FL E E5 L W1C IT RT A M 00 T TU A A. I M B KS C OL Filed Feb. l2, 1965 uunono coo May 9., 119%? A. MILLER ETAL LOCKEDACTIO EMI N RIFLE FOR AUTOMATIC AN!) -AUTOMATC SELECTIVE FIRING FiledFeb. 12, 1965 8 Sheets-Sheet 3 May 11967 A. MiLLER ETAL EEMJQZ LOCKEDACTION RHLE FOR AUTOMATIC AND SEMI-AUTOMATIC SELECTIVE FIRING 8Sheets-Sheet 4 Filed Feb. 12, 1965 5 t e e h S S t e 8 mm W 8 G CN HI mF O TE U V MI T E C E R m EM 5 LF lm RM M M A M U i I D M E E S O L May9, 119%? Filed Feb. 12, 1965 May 9, @967 A. MILLER ETAL 3,3]1&i92 LOCKEDACTION RIFLE FOR AUTOMATIC AND SEMI -AUTOMATIC SELECTIVE FIRING 8Sheets-Sheet Filed Feb. 1.2, 1965 BBMJQZ May mm A. MILLER ETAL LOCKEDACTION RIFLE FOR AUTOMATIC AND SEMI-AUTOMATTC SELECTIVE FIRING FiledFeb. 12, 1965 8 Sheets-Sheet 7 May 9, 19%? A. MILLER ETAL 3,318,392

LOCKED ACTION RIFLE FOR AUTOMATIC AND SEMI-AUTOMATIC SELECTIVE FIRING 8Sheets-Sheet 8 Filed Feb. 12, 1965 3,318,192 IJUCKED ACTIUN RIFLE FURAUTUMATIL' AND SEMI-AUTUMATIE SELEETIVE FIRING Arthur Miller and CharlesEl. Dorehester, Costa Mesa,

and George 11. Suilivan, North I-Ioilywooi'tlalii, as-

signors to Armalite, line, Costa Mesa, Califi, a corporation ofCaiifornia Fiied Feb. 12, 1965, Ser. No. 432,198

8 Claims. (1T1. Ss -1 12) This invention relates to a combat rifle, moreparticularly a combat rifle that can be fired in automatic orsemiautomatic sequence and which will maintain the maximum ofperformance under adverse combat conditions.

It is well known that firing performance can be achieved in manystructural arrangements of receiver, bolt, bolt carrier and action butin all instances, the parts are machined for close tolerance to achievean excellence of performance but the same features defeat the purposefor performance under adverse combat conditions. By this is meant, theprecision machining that goes into the forming of the parts and theinterfitting of parts in relation to other parts for high performancerequires such close tolerances that the precision achieved by the rifleformed with such parts is defeated if the rifle is subjected to combatconditions of water, sand, grime, dirt etc.

The machining operations which produce the superior performance of theparts in other rifles also increases the cost of parts and the cost ofthe machines to produce the parts and thereby renders such a rifleuneconomical in mass production.

It is, therefore, an object of this invention to provide a rifle thatcan be used in an automatic or semi-automatic firing sequence at willthat will be economical to produce by reason of the fact that manyimportant parts are made from sheet metal stampings and assembled intosheet metal weldments.

It is another object of this invention to produce a combat rifle thatwill perform under adverse conditions by reason of the nature of theconstruction of the parts and employing principally sheet metal partsand eliminating close tolerances.

It is another object of this invention to provide an automatic and/orsemi-automatic combat rifle of simplified construction employing amaximum number of sheet metal parts and sheet metal weldments and aminimum number of machined parts to reduce the maintenance and trainingto a minimum.

It is a further object of this invention to provide a construction anddesign of an automatic rifle having sheet metal parts which lack closetolerances and therefore will sustain rough handling, dust, dirt, mud,sand and extremes of heat and cold and yet will maintain accuracy undersustained fire.

Further and other objects of this invention will be understood from thedescription of the accompanying drawings in which like numerals refer tolike parts.

In the drawings:

FIGURES 1a and 1b together constitute a longitudinal side view partiallyin section, of the rifle from the butt stock to the muzzle.

FIGURE 2 is a side view partially in section of the action, receiver,and rear portion of the barrel.

FIGURE 3 is a top plan view of the lower portion of the receiver,showing the sheet metal construction of the parts.

FIGURE 4 is a side elevation partly in section of the bolt carrier takenon the line t4l of FIGURE 5.

FIGURE 5 is an end view of the bolt carrier.

FIGURE 6 is a sectional assembly view of the bolt carrier, bolt, andguide rod assembly taken on line 6-6 of FIGURE 7.

States Patent 0 FIGURE 7 is an end view of the bolt and bolt carrierassembly.

FIGURE 8 is a sectional view of the guide rods for the bolt carrier.

FIGURE 9 is a section of an alternate form of guide rods for the boltcarrier.

FIGURE 10 is an end view receiver.

FIGURE 11 is a side elevational view partly in section showing the upperportion of the receiver secured to the barrel.

FIGURE 12 is an end view of the receiver taken on the line 1212 ofFIGURE 13.

FIGURE 13 is a bottom view of the sheet metal receiver attached to thebarrel as shown in FIGURE 11.

FIGURE 14 is an assembly view of the hammer, trigger, and disconnect.

FIGURE 15 is a fragmentary end view of the hammer, trigger, anddisconnect assembly shown in FIGURE 14, viewed as shown by arrow A.

FIGURE 16 is a rear end view of the auto sear assembly.

FIGURE 17 is a side elevational view of the auto sear assembly.

FIGURE 17a is a fragmentary plan view of the connecting link of FIGURE17.

FIGURE 18 is a rear end elevational view of the barrel extension.

FIGURE 19 is a side sectional view of the barrel extension, taken on theline 19-19 of FIGURE 18.

FIGURE 20 is a front elevational view of the barrel extension.

FIGURE 21 is a side elevational view partly in section showing the lastround stop bolt catch assembly.

FIGURE 22 is an end elevational view of the bolt catch assembly.

FIGURE 23 is an end elevational view of the selective firing lever.

FIGURE 24 is a side elevational view of the selective firing lever andcam shaft connected thereto.

FIGURE 25 is a top view of the selective firing lever and cam shaftshown in FIGURE 24.

FIGURES 26 through 29 are sectional views of the selective firing levercam taken on the lines respectively 2626, 27-27, 2828, and 2929 ofFIGURE 24.

The automatic rifle shown in FIGURES la-lb has the usual components of abarrel 1 and a receiver generally indicated as 2. The barrel is threadedinto a barrel extension 3. Gas is taken from cylinder assembly 4 uponfiring to actuate a push rod or actuating rod 5 to actuate the boltcarrier generally indicated as 6. A locking bolt 7 engages lugs in therearward portion of barrel extension 3 to secure the firing chamber aswill be later described.

The function and operation of the operating rod and gas cylinder aredescribed in copending application Ser. No. 375,256, filed June 15, 1964'by Arthur Miller, which matured into U.S. Letters Patent No. 3,246,567on Apr. 19, 1966. The function and operation of the barrel extension andthe bolt are the subject matter of Patent No. 3,027,672, filed Apr. 26,1961 and issued to George C. Sullivan, Apr. 3, 1962.

In FIGURE 1a, are shown upper receiver 8 and lower receiver 9, hinged at10 so that the portions of the receiver can be separated as shown inFIGURE 2, for disassembly and maintenance. A butt stock 11 is secured tolower receiver 9 and catch 12 permits unlatching the folding of buttstock 11 for positioning against the side of receiver 2. Pistol grip 13is secured to lower receiver 9. Trigger guard 14, magazine guide 15 andrear bracket 16 comprise integral components of the lower receiver 9.Trigger assembly 17, fire selection cam 168,

of the upper portion of the hammer 120 and last round stop mechanism 150are carried by lower receiver portion 9. Housed and carried by upperreceiver portion 8 are automatic sear mechanism 19 and bolt carrier 6which moves on a pair of guide rods 21. Channel 22 is welded to the sideof upper receiver portion 8.

The parts described above in connection with the general description ofthe rifle can be more clearly noted in their respective relationship inFIGURE 2 which shows the upper receiver portion 8 pivoted away from thelower receiver portion 9.

One of the principal features of upper receiver portion 8 is that it ismade of sheet metal, bent and formed into a receiver portion. As will beseen from FIGURES 10 to 13 and FIGURES 18 to 20, receiver portion 8 issheet metal stamping bent to form a generally rectangular, elongatedtube having suitable apertures and extensions to accommodate the partsmounted thereon. The sheet metal forming receiver 8 is joined and weldedas shown at 23 and 24 on the under side of the receiver. The sightingbracket 25 is also formed of a sheet metal stamping and is shown weldedto the rear upper portion of receiver portion 8.

Sight 25a is a two position sight formed of sheet metal and pivoted at25b, biased in one of two positions by spring 250.

The left hand end of the tubular member forming receiver portion 8 isshown open in FIGURES 10 and 11. The right hand end of the tubularmember forming receiver portion 8 is closed by barrel extension 3illustrated in FIGURES 18 to 20. FIGURE 20 shows an end view of barrelsleeve extension 3 which fits within the formed sheet metal tubularmember 8 and is welded thereto to close the right hand end. An extension26 of member 3 has an aperture 27 formed therein to accommodate alocating lug 28 on the rear portion of the lower part of the hand guard29 shown in FIGURES la-lb. The forward and rearward flanges on sleeveextension 3 have other apertures formed therein. Apertures 30 and 31perform a similar function, that of a guide for operating rod 5.Apertures 33, 33' and 34, 34' position guide rods 21 within upperreceiver portion 8. Sleeve 3 is threaded as shown at 35 to receive thecorrespondingly threaded portion of the rear end of barrel 1. Lockinglugs 36 are formed on the end opposite the threaded portion of barrelextension sleeve 3 to engage corresponding locking lugs on the forwardend of the bolt in a manner described in Patent No. 3,027,672 referredto above. Depending portions 37 have apertures 38 formed therein toaccommodate a hinge pin 10 to permit hinging of the upper and lowersections of the receiver.

Referring to FIGURES 10 to 13, it will be seen that sleeve extension 3forms support for, and completes the right hand end of upper receiverportion 8. The left hand end of the upper receiver portion shown in FIG-URE 11, is open. Formed with or attached to the sheet metal constructionof receiver portion 8 are members 39 depending therefrom having holes 40to afford a pivot point for support for the automatic sear mechanism 19.

It will be noted that the top, forward end, and left hand side of upperreceiver portion 8 are closed. The lower portion has apertures 41 and 42to accommodate the operating mechanism but are closed when in theassembled relationship with the lower portion of the receiver 9. Theright hand side of the receiver portion 8 has an elongated aperture 43to accommodate the ejection of cartridge shells and the rearward motionof a cocking lever.

The rectangular shape of upper receiver portion 8 is maintained by beingwelded to sleeve member 3 on the forward end, bridge member 44intermediate the sides in which is weld 24 and intermediate member 45 atthe right hand end in which is weld 23.

FIGURE 2 shows the left hand end of upper receiver portion 8 partiallyclosed by guide rod plate 46 having a guide plate rod handle 47 weldedat the middle of the top portion thereof. Guide rods 21 extend throughopenings in plate 46 and are welded therein to form a welded assembly ofa pair of guide rods 21, plate 46, and handle 47. The guide rods haveportions 21 extenting through the plate for a purpose that will be laterdescribed.

The lower portion of the receiver 9 is also a metal stamping, bent andwelded to form a sheet metal construction. As will be seen from FIGURES1a, 2 and 3 the sheet metal weldment 9 is formed with a portion 15adapted to receive a magazine 15'. The right hand end of receivingportion 9 is formed with members 50 adapted to receive portions 37 ofsleeve extensions 3 and form support for pin 10. Partition 51 is securedbetween the side walls of lower receiver portion 9 to form a back wallfor the magazine chamber 15. Portions 52 formed inwardly on the sidewalls of chamber 15 form an upper limit stop for the magazine chamber.Rearward portion of the lower receiver portion 9 is completed by bracket16 which is in the form of a bent and welded sheet metal assembly towhich the sides of the lower receiver assembly 9, 9, and 9 are welded.The forward wall of bracket 16 shown in FIGURE 2 as 16', has a pair ofapertures 18 through which extend the ends of guide rods 21' and a cutout portion 52 to accommodate handle 47. The upper receiver assembly ispivoted into position with the lower receiver assembly. Guide rod handle47 is pressed forwardly with the thumb to move member 46 against springs53 surrounding guide rods 21 so that guide rod portions 21 may registerwith holes 18 and forward wall 16 of bracket 16 and when releasedportions of guide rods 21' will extent through holes 18 and lock the twoportions of the receiver in operative position. Brackets 54 extendrearwardly of member 16 to afford a hinge and catch for folding buttstock 11.

Magazine 15' is shown having a plate 55 biased upwardly by spring 56 tourge the cartridges into position to be carried into the chamber of therifle. A ledge on the rearward portion of plate 55, numbered 57, engagesthe last round stop lever 58 as will be described in more detail inconnection with FIGURES 21 and 22. The hammer and trigger assembly areshown mounted in the lower receiver portion and will be described inmore detail in connection with FIGURES 14 and 15.

A safety holder detent 60 for selectively firing safety mechanism isshown in FIGURE 3 extending through forward wall 16' of bracket 16 andis guided therein and further is biased by a spring 61 in the forwardposition.

In FIGURES 4 to 7 is shown in more detail, the bolt carrier and thebolt. Bolt carrier 6 is an elongated block of a cross section to fitwithin the generally rectangular tubular receiver portion 8 but withsuificient clearance on all sides. It is designed to have ampleclearance or space all around the bolt carrier. It is supported entirelywithin upper receiver portion 8 on rods 21 extending through openings 78formed therein throughout the length thereof which engages rods 21 witha sliding fit. Ribs 71 extend along the top of bolt carrier 6 and affordrunners 71. Runners 71 are adapted to ensure clearance and the spacingof the block from the inside upper wall of receiver portion 8. Member 72is a shock absorber mounted in cavity 74 formed in bolt carrier 6. Theshock of the impact of the bolt carrier on plate 46 at the ends of guiderods 21 is absorbed by spring 73. Tubular pin 75 extends through theblock of bolt carrier 6 for disassembly purposes. A pin 76 extends fromthe right hand side of the bolt carrier 6 shown in FIGURE 5 and rides intrack 22 which track is welded or otherwise secured to the inner leftside Wall of receiver portion 8. Pin 76 will be hereinafter referred toas a track pin. As shown in FIGURE 4 a cam slot 80 is formed in the sidewall of bolt carrier 6. Chamber 81 is formed in the bolt carrier toaccommodate the bolt. The rear portion of chamber 81, shown at 82,accommodates a spring 86 to bias firing pin 83 as shown in FIGURE 6. Pin84 extends through the bolt carrier and engages a flange 85 on thefiring pin to retain the firing pin and the entire assembly in place butpermitting ready removal of the firing pin, spring, bolt, and cam pinfor disassembly purposes.

FIGURES 6 and 7 show the bolt carrier 6 having assembled in cavity 81, abolt 90. The bolt is of the type described in Patent No. 3,027,672 andhas locking lugs 91 to engage corresponding locking lugs 36 of thesleeve extension 3 on the barrel of the rifle. An extractor mechanism isshown at 92 and an aperture for the firing pin at 93.

In FIGURE 6, bolt 90 is shown positioned in cavity 81 formed in boltcarrier 6. Bolt 90 is free to move axially of the cavity 81. As it movesin cavity 81, it slides on firing pin 83. A cam pin generallycylindrical in shape is shown at 94. It extends through bolt 90 andoutwardly through cam opening 80 beyond the outside wall of the boltcarrier 6 as shown in FIGURE 7. Cam pin 94 has an aperture formed therinthrough which firing pin 83 extends to hold the bolt and cam pin inassembled relationship but permits easy disassembly. When cam pin 94 isin the right hand end of the cam slot 80 as shown in FIGURE 4, the boltis in the unlocked position and cam pin 94 slides with pin 76 in track22, during the rearward motion of bolt carrier 6. Upon forward motion ofbolt carrier 6 the bolt closes the cartridge chamber fomed in the barreland locking lugs 91 mesh with locking lugs 36 and sleeve extension 3.Cam pin 94 is then beyond the forward extent of track 22. Furtherforward motion of bolt carrier 6 causes cam pin 94 to rotate counterclockwise as viewed in FIGURE 7 which in turn causes a counter clockwiserotation of the bolt so that locking lugs 91 engage and lock withlocking lugs 36. Clockwise rotation of locking lugs 91 with respect tolugs 36 takes place when the bolt carrier moves rearwardly impelled byoperating rod 5. Cam pin 94 is then rotated to the position to bealigned with track 22 and remain in track 22 during the completerearward motion of the bolt carrier 6.

In FIGURES 4- and 5, bolt carrier 6 is milled to provide an extension 95to engage the hook 1113 of the auto matic sear as will be described inconnection with FIG- URE 17.

FIGURE 8 shows guide rod 21 of round cross-section whereas FIGURE 9shows guide rod 21a in an alternate form with flat portions spaced 120apart to give adequate bearing surface but will atford greater clearancefor self cleaning action.

FIGURES 16, 17 and 17a show the automatic sear connecting link for theautomatic release of the hammer for automatic firing. The assembly shownin FIGURES 16, 17 and 17a is secured by a pin extending through the holein bushing 1619 and holes 441 in member 39 forming a part of the upperreceiver portion 8. The assembly is therefor secured to and functionswith the upper receiver portion 8. Member 19 is a sheet metal stampingbent in a generally U-shaped form so that side members 19 and 19a alfordend bearings for bushing 11111, and portion 1115 extends between sidemembers 19, 19a. Member 19 is formed with a surface 1414 that cooperateswith the safety or selective firing cam 168 as will be described later.Portion 105 forms the automatic sear for a trigger release for automaticfiring. Automatic firing connecting link 1111 is pivoted to 19 at 1132.Link 101 extends inside of upper receiver portion 8. In FIGURE 11 aheaded member 110 is shown which is engaged by slot 1116 formed in theforward end of link 101. Link 101 is twisted 90 degrees from a verticalposition at the end near pivot 102 to a horizontal position at the endin which is formed slot 1116. The forward end of link 101 is formed witha vertical portion 111 adjacent slot 106. Portion 111 has a ramp portion107 and a scar portion 1113. Portion 111 slides in a slot in boltcarrier 6 shown at 112 in FIGURE 4. As bolt carrier 6 moves rearwardly,portion 111 moves along slot 112 formed in bolt carrier 6. When therifle is set for full automatic operation the forward motion of the boltcarrier 6 under the energy stored in springs 53 shown in FIGURE 2 causesprojection as shown in FIGURE 4 to engage surface 163 and move theconnecting link 1111 forwardly. Sear surface disengages the hammer, aswill be described in more detail, which will fire the cartridge in thechamber through firing pin 83.

The structure illustrated in FIGURE 14 consists of the hammer 120, thetrigger 17 and a trigger disconnect 121. Trigger 17 is made from afolded metal stamping having side portions 17a and 17b. The sideportions are held in space relationship by the bent portion of the metalforming the actual trigger portion engaged by the finger of the personfiring the gun. Member 122 on the left hand end of trigger 17 is weldedin place and spaces trigger portions 17a and 17b. Trigger 17 is ineffect a bell crank pivoted about pin 124. Spring biases trigger 17 in aforward position. The end of spring 125, shown in FIGURES l4 and 15, isshown in FIGURE 2 resting on the bottom of lower receiver assembly 9 totension the spring. Surfaces 123 on members 17a and 17b are engaged bythe safety or selective firing cams to hold portions 17a, 17b in adownward position to prevent actuation of any of the mechanism or thetrigger being moved when in the safe position.

Trigger disconnect 121 is mounted on pivot 124 and is a single metalstamping as shown in FIGURE 15 and mounted in the space between sides17a and 17b of the trigger. A compression spring 126 is supported on thelower side by two turned-in portions 127 of sides 17a and 17b andpresses against trigger disconnect 121 on the top to bias triggerdisconnect in a clockwise direction with respect to the triggerassembly. A hook portion 129 on the trigger disconnect 121 extendsthrough an opening between the two sides of hammer 1211 to engageportion 136 of the hammer to lock the hammer in the down position.

The function of the trigger disconnect 121 is to engage and hold hammer120 when trigger assembly 17 is in the clockwise position. When trigger17 is pulled rearwardly, spring 126 is compressed and disconnect 121 isrotated and held in a clockwise position. Normally hook 129 ofdisconnect 121 moves freely through the opening in the forward side ofhammer 1211 when the trigger is in the normal or counterclockwiseposition. However, when the trigger is moved rearwardly, hook 129 willlatch over portion 1311 of hammer 1211 and hold it until trigger 17moves forwardly taking the sear along by means of pin 122 againstsurface X and hook 129 will release the hammer and engage surfaces 131and 132. After firing, while the trigger is held in a back position,bolt carrier 6 will depress hammer 121) and spring 126 will permit hook129 to engage and hold 136, thus holding the hammer until the trigger isreleased.

Hammer 12! is formed with a sear surface 132 which engages the searsurface, on the trigger, 131 for semiautomatic firing. Hammer 1211 ismounted in the lower receiver portion 9 by pin 133 and biased in aclockwise direction by spring 134 as shown in FIGURE 2. As shown inFIGURES 3, 14, and 15 hammer 126 is also of sheet metal constructionfolded to provide flat parallel sides 120a and 1201). A notch is formedin the upper portion of the hammer affording a sear surface 135 whichcooperates with portion shown on FIGURE 17 for the automatic firing ofthe rifle.

The last round stop mechanism is illustrated in FIG- URES 21 and 22taken in conjunction with FIGURES la and 2. The last round stop consistsof a lever 15d mounted at a pivot 151 on the side of the lower receiverassembly 9. It has a hook portion 152 which extends upwardly into upperreceiver portion 3. It has a portion 58 formed on the forward endthereof which extends into and engages or is engaged by portion 57 ofthe follower 55 in magazine A button 154 is urged upwardly by arelatively weak spring 153 which is mounted on lever arm 150 to holdhook portion 152 out of the path of bolt carrier 6. Lever 150 has arelatively long lever arm from pivot point 151 to the end of member 58.Therefore if the magazine spring is weak, due to the length of the leverarm, a good mechanical advantage will be had after the last round topush hook portion 152 up into the path of travel of bolt carrier 6. Itwill be seen therefor from FIGURE 1a that when hook portion 152 is notheld downwardly out of the path of travel of bolt carrier 6 by spring153, it will engage bolt carrier 6 and hold the bolt carrier in the openposition. It should be pointed out that button 154 rests against crossmember 44 on the lower side of upper receiver portion 8.

FIGURES 23-29 illustrate the safety or firing selection lever which ismounted on the left hand side of the lower receiver portion 9 asillustrated in dashed lines in FIGURE 2. The lever 165 has a handle 166and a pointer 167. In the vertical position of the handle as shown inFIGURE 23'with pointer 167 pointing upwardly, the rifle is in thesemi-automatic firing condition. When pointer 167 is movedcounterclockwise, the rifle mechanism is in the safe condition. When thepointer 167 is moved clockwise the rifle mechanism is in the automaticcondition. The selective firing or the safe condition of the firingmechanism is accomplished by the shaft being milled or formed into a cam168 throughout its length with cross sections illustrated at spacedpositions along a shaft as shown by FIGURES 2629. The portions of thecam shaft or the cutouts in the cam shaft either lock portions of thefiring mechanism from operating or permit motion of other parts of thefiring mechanism by moving int-o and out of the recesses formed in thecam shaft.

The detent 60 has the forward end biased by spring 61 to engage one ofthe three notches shown in FIGURE 26 for the safe, semi, or the autoposition of lever 165.

It will be noted in connection with FIGURE 1a and FIGURES 16 and 17 thatmember 19 is biased so that sear surface 104 moves counterclockwise.Automatic sear connecting link 101 will be biased toward the left asshown in FIGURE 17. If the fire selection lever is moved to theautomatic position (auto), there will be a cutout portion in cam shaft168 which will permit surface 104 to move freely in a counterclockwisedirection. This will permit automatic sear connection link 101 to movesurface 103 to the left in FIGURE 17. It will be engaged by the boltcarrier 6 in the last portion of the travel of the bolt carrier afterthe bolt has closed and locked the chamber. This last fractionalmovement of surface 103 will cause surface 105 of FIGURE 17 to move in aclockwise direction and disengage surface 135 of hammer 120 and releasethe hammer. If the fire selection lever is moved to a semi-automatic orsafe position, the cam surface on 168 will move surface 104 in aclockwise direction so that surface 103 of FIGURE 17 will not be engagedby the bolt carrier and therefore automatic firing will not take place.It will either be safe against any firing or will operate with aseparate mechanism for semi-automatic firing.

It will be noted in FIGURE 10 that as bolt carrier 6 moves rearwardlyunder the impact from the gas operated push rod 5, that the rear portionof bolt carrier 6 presses the upper portion of hammer 120 into the lowerreceiver portion 9. If the fire selection switch is set for automaticfiring, portion 105 of member 19 will move in a counterclockwisedirection and will engage and stop portion 135 of the hammer 120 untilreleased by the forward motion of the bolt carrier as described above.If, as described above, the automatic firing is locked out by theposition of the fire selection lever, then members 105 and 135 will notengage and the hammer then will be held by sear surfaces 131 and 132being engaged. If

surface 123 of trigger 17 is held downwardly by portions of the camshaft 168 and fire selection lever 166 then it will be impossible tomove the trigger rearwardly about its pivot to fire the gun and the gunwill be in a safe condition.

The operation of the rifle is as follows: there are two separate firingsystems, one for automatic and one for semi-automatic firing. If thefull automatic sear system is removed or damaged the rifle can be firedin a semiautomatic condition.

Assumed condition of weapon, i.e., bolt closed on an empty chamber,hammer cocked as in FIGURE 14, selective fire lever either on safe,semi, or auto, then (1) On Safe condition By rotating selective firelever (FIGURES 24-2 9) to safe position: (a) the automatic sear iscammed out of engagement position, i.e., surface 104 (FIGURE 17) iscammed clockwise by the selective fire lever, and (b) trigger 17 anddisconnect 121 are blocked, i.e., trigger surface 123 and disconnectsurface 128 rest against outside diameter of selective fire lever, thuspreventing clockwise rotation. Counter clockwise rotation of trigger isprevented by hammer.

(2) Semi-automatic or Semi condition Having fed a live round in thechamber while the weapon is on safe, the selective fire lever is rotatedto semi position, as shown in FIGURE 24.

(a) The automatic sear remains cammed out of engagement position.

(b) The trigger and disconnect are now allowed to rotate clockwise. Bypulling on the trigger (clockwise), the hammer is released. Havingreleased the hammer, by disengaging surfaces 131 and 132, FIGURE 14,further clockwise rotation of the trigger-disconnect assembly, inexactly the same relationship as shown in FIGURE 14, is limited by thecutout, FIGURE 28, and contact surfaces 128 and 123, FIGURE 14.

The hammer, after impinging upon the firing pin and discharging thecartridge, is rotated counterclockwise by the bolt carrier. Since thetime span for the above cycle, i.e., firing and recocking, is only asmall fraction of a second, the trigger finger of the shooter does nothave enough time to release the trigger, i.e., to allow the triggerspring to rotate the trigger counter-lockwise and thus engage surface132 with trigger surface 131. Therefore, the disconnect claw 129 isfirst cammed counter-clockwise by hammer surface 130, then snaps overand catches the hammer at 130.

The trigger, still held by the trigger finger against the cutout in theselective fire lever, gradually relaxes, thus permitting the triggerspring to rotate the trigger with disconnect counter-clockwise, wherebythe trigger forces the disconnect counter-clockwise by means of pin 122and surface X.

This counter-clockwise rotation is continued until surfaces 129 and 130disengage at which time the trigger catches the hammer at 131 and 132surfaces.

The weapon has now completed its cycle and is again ready to fire.

(3) Full automatic or Auto condition By rotating the selective firelever to auto position:

(a) The cam shaft portion (FIGURE 24, section 2828) on the selectivefire lever blocks the disconnect 121 as in safe position, i.e., the camshaft portion (FIGURE 24, section 2828) cams surface 128 of thedisconnect counter-clockwise. The disconnect is now prevented fromfunctioning during the automatic cycle.

(b) The automatic sear is now biased counterclockwise by the spring,i.e., assuming the hammer being held by the trigger (as in FIGURE 14,131 and 132) the sear will rotate counter-clockwise until surface Ycontacts radius Z on hammer. If the hammer is now released by pullingthe trigger and the trigger remains pulled (all the way clockwise),i.e., surfaces 131 and 132 can no longer engage as the hammer is beingcocked by the return stroke of the bolt carrier. The hammer (radius Z),in its counterclockwise rotation strikes surface Y on the sear, cammingit clockwise (momentarily).

Then, as the hammer continues its counter-clockwise rotation, cutout 135in the hammer allows the sear spring to snap the sear counter-clockwiseinto the cutout and eventually engage surfaces 105 and 135. In themeantime, the bolt carrier has reached the end of its rearward strokeand glides forward (feeding a new cartridge). The bolt carrier thenlocks the bolt and strikes surface 103 of the sear extension (FIGURE 17)and releases the hammer by causing the sear to rotate clockwise.

The above cycle is repeated until the magazine is empty or until thetrigger is released (and surfaces 131 and 132 engage) in which case theauto-cycle is interrupted.

It should be clear from the foregoing description that certain changes,alterations, modifications and substitutions can be made withoutdeparting from the spirit and scope of the depending claims.

What is claimed is:

1. In a locked action rifle for automatic and semiautomatic selectivefiring, an upper receiver portion comprising sheet metal formed into agenerally rectangular tube, a lower receiver portion comprising a sheetmetal box of a length and width generally coextensive with said upperreceiver portion, and an action housed within said upper receiverportion and said lower receiver portion, said action including a triggermechanism made up of elements substantially all of which are made fromsheet metal stampings; hinge portions formed on the forward ends of saidupper and lower receiver to afford a hinge about a transverse axis,means to mount a barrel provided on the forward end of said upperreceiver portion, a pair of guide rods mounted in said upper receiverportion, springs surrounding said guide rods, a bolt carrier membermounted on and guided by said guide rods to move within said upperreceiver portion substantially free of the walls of said upper receiverportion, a bolt in said bolt carrier, means to rotate said bolt to lockand unlock said bolt from engagement with means on the rearward end ofsaid barrel, a channel member stamped from sheet metal and securedinside said upper receiver portion and extending longitudinally thereof,said means to rotate said bolt including a pin member secured to saidbolt carrier and engaged and guided by said channel member duringmovement of said bolt carrier, and latch means to secure said upper andlower portions together in the firing position.

2. A locked action rifle as defined in claim 1 wherein said latch meansincludes, a bracket of sheet metal, said bracket having a lower portionconnected to the sides of the lower receiver assembly and an upperforward portion with apertures therein for the reception of the ends ofsaid guide rods which extend through a member welded at the end of theupper receiver portion, means connected to said member to move saidmember against said springs surrounding said guide rods'when the upperreceiver assembly is pivoted into position with the lower receiverassembly whereby said guide rods may register with said apertures andextend through said apertures to lock the two portions of the receiverin operative position.

3. A locked action rifle as defined in claim 2 including a folding buttstock and a pair of rearwardly extending members connected to saidbracket providing a hinge and catch for said folding butt stock.

4. A locked action rifle as defined in claim 1 including a plurality ofribs extending along the top of said bolt carrier providing runners toinsure the clearance and the spacing of the bolt carrier from the insideupper wall of the upper receiver portion.

5. A locked action rifle as defined in claim 1, including a rearsighting means, said sighting means comprising a sighting bracket formedby sheet metal stamping and welded to the rear upper portion of saidupper receiver portion, a two position sight formed of sheet metal andpivotally mounted on said sighting bracket so that either of saidpositions may be manually selected, and spring biasing means mountedbetween the top of said upper receiver portion and said two positionsight for biasing said two position sight in the position selected.

6. A locked action rifle for automatic and semiautomatic selectivefiring as defined in claim 5 wherein said lower receiver portionincludes a strip of sheet metal formed to provide a trigger guard and atransverse partition of sheet metal spaced from the forward end of saidlower receiver portion to form a magazine receiver.

7. In a rifle for automatic and semi-automatic selective firing, anupper receiver portion comprising sheet metal formed into a generallyrectangular tube, a lower receiver portion comprising a sheet metal boxof a length and width generally coextensive with said upper receiverportion, an action made up of elements housed within said upper receiverportion and said lower receiver portion, hinge portions formed on theforward ends of said upper and lower receiver portions to afford a hingeabout a transverse axis, means to mount a barrel provided on the forwardend of said upper receiver portion, a pair of guide rods mounted in saidupper receiver portion, a bolt carrier mounted on and guided by saidguide rods to move within said upper receiver portion substantially freeof the walls of said upper receiver portion, a bolt in said boltcarrier, means to rotate said bolt to lock and unlock said bolt fromengagement with means on the rearward end of said barrel, said actionincluding a trigger formed from a metal stamping folded to form two sideportions and pivotally mounted in said lower receiver portion, a spacingmember welded to and between said side portions, said trigger having asear thereupon, a hammer of sheet metal construction folded to provideparallel sides, said hammer having a sear abutment thereupon engageableby said sear on said trigger, an automatic sear abutment at the oppositeextremity from said trigger sear abutment and a slot in its leading faceintermediate its extremities, a trigger disconnect formed from a singlemetal stamping and pivotally mounted between the side portions and saidtrigger and extending through the slot in said hammer so as to beengageable with the leading face of said hammer, an automatic searmechanism pivotally mounted in the upper portion of said receiveradjacent said hammer and engageable with said automatic sear abutment onsaid hammer, said automatic sear mechanism including a sear extension topermit the utilization of a short bolt carrier, and a selective firingcontrol means mounted for rotation in said receiver and located betweenadjacent extremities of said automatic sear mechanism, said trigger andsaid trigger disconnect to determine the operating conditions of saidautomatic sear mechanism, said trigger and said trigger disconnect.

3. A rifle for automatic and semi-automatic selective firing as definedin claim 7, wherein said control means includes a rotatable memberhaving a plurality of cam surfaces thereupon engageable, respectively,with said trigger, said trigger disconnect mechanism and said automaticsear mechanism to determine the relative positions and operation of saidelements, said rotatable member also including a notched surface havingthree notches, a handle connected to said rotating member for rotatingsaid member to any one of three positions, safety, semiautomatic orautomatic, a detent mounted in the lower receiver portion and a springconnected to said detent biasing said detent into one of said notches,the particular notch into which said detent is biased being determinedby the position of said handle.

(References on following page) References Cited by the Examiner UNITEDSTATES PATENTS Haubroe 4275 Petter 42-75 5 Sampson et a1. 42--16 Kolinko42-75 Harvey 89185 Wooderson 89142 12 3,045,555 7/1962 Stoner 89-1423,153,295 10/1964 Allyn 42 75 FOREIGN PATENTS 613,281 11/1948 GreatBritain.

BENJAMIN A. BORCHELT, Primary Examiner.

S. C. BENTLEY, Assistant Examiner.

7. IN A RIFLE FOR AUTOMATIC AND SEMI-AUTOMATIC SELECTIVE FIRING, ANUPPER RECEIVER PORTION COMPRISING SHEET METAL FORMED INTO A GENERALLYRECTANGULAR TUBE, A LOWER RECEIVER PORTION COMPRISING A SHEET METAL BOXOF A LENGTH AND WIDTH GENERALLY COEXTENSIVE WITH SAID UPPER RECEIVERPORTION, AN ACTION MADE UP OF ELEMENTS HOUSED WITHIN SAID UPPER RECEIVERPORTION AND SAID LOWER RECEIVER PORTION, HINGE PORTIONS FORMED ON THEFORWARD ENDS OF SAID UPPER AND LOWER RECEIVER PORTIONS TO AFFORD A HINGEABOUT A TRANSVERSE AXIS, MEANS TO MOUNT A BARREL PROVIDED ON THE FORWARDEND OF SAID UPPER RECEIVER PORTION, A PAIR OF GUIDE RODS MOUNTED IN SAIDUPPER RECEIVER PORTION, A BOLT CARRIER MOUNTED ON AND GUIDED BY SAIDGUIDE RODS TO MOVE WITHIN SAID UPPER RECEIVER PORTION SUBSTANTIALLY FREEOF THE WALLS OF SAID UPPER RECEIVER PORTION, A BOLT IN SAID BOLTCARRIER, MEANS TO ROTATE SAID BOLT TO LOCK AND UNLOCK SAID BOLT FROMENGAGEMENT WITH MEANS ON THE REARWARD END OF SAID BARREL, SAID ACTIONINCLUDING A TRIGGER FORMED FROM A METAL STAMPING FOLDED TO FORM TWO SIDEPORTIONS AND PIVOTALLY MOUNTED IN SAID LOWER RECEIVER PORTION, A SPACINGMEMBER WELDED TO AND BETWEEN SAID SIDE PORTIONS, SAID TRIGGER HAVING ASEAR THEREUPON, A HAMMER OF SHEET METAL CONSTRUCTION FOLDED TO PROVIDEPARALLEL SIDES, SAID HAMMER HAVING A SEAR ABUTMENT THEREUPON ENGAGEABLEBY SAID SEAR ON SAID TRIGGER,